In the prior art numerous devices have been proposed and used for setting and resetting fire dampers of the type known as "curtain" dampers. These dampers are mounted in frames which fit into air ducts so as to close like a curtain; dropping when a heat actuated link disengages the retaining wire holding the folded curtain in a folded condition at the top of a frame. In order to test the device periodically, it is desirable to release and reset it. In order to accomplish this, it is necessary to have an access door to give access to the duct work containing the damper, and thus provide access to the damper control mechanism.